Preparation,Microstructure And Infrared Stealth Property Of Aluminum Doped Zinc Oxide

With the development of modern military industry,infrared stealth materials have been widely used.Doped oxide semiconductor materials can achieve infrared stealth by controlling the doping concentration,so that the material has low emissivity in the infrared band.Zinc oxide doped with aluminium(ZAO)has excellent photoelectric properties comparable to indium oxide doped with tin(ITO),but its raw materials are cheaper and its yield is higher,so it is more ideal as infrared stealth material.Aiming at the special application of aircraft radome,a low infrared emissivity stealth material with high radar transmittance was prepared by adjusting the preparation process,using ZAO as filler and EPDM as base.In this paper,zinc nitrate and aluminum nitrate solutions were selected as the main reactants,and the experiment was carried out by one-step method and two-step method.In the two-step experiment,the relationship between different calcination temperatures,zinc-aluminium doping ratios and the structure morphology of ZAO products was investigated.In the one-step method,the structures of ZAO products with different zinc-aluminum doping ratios and different surfactants were investigated.Morphology and its effect on the crystal growth mechanism during hydrothermal synthesis.It was found that the products obtained by the two-step experiment were mostly spherical particles;when one-step synthesis,the choice of surfactants had a great influence on the morphology of the product.When NaOH is used as the mineralizer,the ZnO product is closer to its original shape without the addition of a surfactant,that is,a hexagonal prism shape.The use of surfactants has an effect on the morphology of the final product.Both sodium tripolyphosphate and acetanilide are beneficial for the formation of flake products,and the average effective diameters of the two groups of product particles are similar.Secondly,Fourier infrared absorption spectroscopy and infrared emissivity analysis of pure ZnO and ZAO were carried out.It was found that the ZAO powder prepared by the two experimental methods was not obvious in the thermal infrared band(8?14?m)of the atmospheric window.The absorption peaks can be used as low emissivity fillers for infrared stealth coatings.EDPM was used as the base material of the composite coating.The substrate was dissolved with different solvents and the infrared absorption characteristics were tested.It was found that the EDPM of cyclohexane as the solvent had the lowest infrared emissivity.Finally,the composite coating was prepared by mixing the filler and the substrate dissolved in cyclohexane as a solvent,and the infrared absorption characteristics of the composite coating were analyzed.As the amount of ZAO added increased,the infrared emissivity of the composite coating increased.Finally,the composite coatings were prepared by mixing fillers and cyclohexane as solvent dissolved substrates.The infrared absorption characteristics of these composite coatings were analyzed.With the increase of ZAO content,the infrared emissivity of the composite coatings increased.